Cellular telephone service providers allow parties to purchase excess capacity in bulk. A provider may allow the purchaser to purchase an amount of capacity in excess of the contracted amount in exchange for a higher rate. The purchaser may use the bulk capacity for a variety of applications.
One such application is to update information in mobile devices. For example, if the mobile devices are vehicle navigation systems containing a conventional cellular telephone subsystem, current traffic information for the navigation system may be updated using the bulk cellular telephone capacity. This allows the users of the devices to obtain travel times between two points. Because traffic information can change rapidly, a significant amount of capacity of the communication network would be required to keep every device updated with current data at all times. To keep costs low, it is desirable to limit the amount of data provided over the communication network.
One way of limiting the amount of data would be to limit updates to times when the device was operating. This arrangement causes some users who use their devices a lot to be heavy users and others to be light users. It would be possible to charge users based on how heavily they use the system, but users who could be charged more may be reluctant to use such a system because the costs could be difficult to anticipate in advance. So it can be undesirable to charge users based on use.
One way of providing certainty in the cost of updating the devices would be to simply cut off service to users who exceed a contracted usage amount. However, such a user may be reluctant to use a system if the user couldn't rely on it being available when it was needed. Another way of providing certainty would be to allow every device to receive all of the updates it needs. One could price the system for the light users and absorb the costs of the heavy users, but such an arrangement might not be profitable. Alternatively, the update service provider could raise prices and charge everyone an average price, but this would force the light users to heavily subsidize the heavy users, and such users may find the system to be too costly. The light users would abandon the system and the update service provider would have to charge ever increasing costs, another undesirable arrangement.
It is thus desirable to allow everyone to pay the same price, but not require light users to heavily subsidize heavy users. However, if all users occasionally use the communication facility less than anticipated, it can be desirable to allow the heavy user to use the capacity of the communication facility so that it does not go unused.
What is needed is a system and method that can update information over a network without exceeding the contracted use of the network, without cutting off heavy users, but without allowing them to significantly exceed an allotment unless spare capacity is available.